public class Circular {
   Circle bottom;
   double height;
   void setBottom(Circle c) { //设置圆锥的底是一个Circle对象
     bottom = c;
   }
   void setHeight(double h) {
     height = h;
   }
   double getVolme() {
     if(bottom == null)
       return -1;
     else  
       return bottom.getArea()*height/3.0;
   }
   double getBottomRadius() {
       return bottom.getRadius();
   }
   public void setBottomRadius(double r) {
       bottom.setRadius(r);
   }
}

